1 / 5

Point to Point protocol (PPP)

Point to Point protocol (PPP). Point to point, wired data link easier to manage than broadcast link: no Media Access Control Several Data Link Protocols: PPP, HDLC…

cale
Download Presentation

Point to Point protocol (PPP)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Point to Point protocol (PPP) • Point to point, wired data link easier to manage than broadcast link: no Media Access Control • Several Data Link Protocols: PPP, HDLC… • PPP (Point to Point Protocol) is very popular: used in dial up connection between residential Host and ISP; on SONET/SDH connections, etc • PPP is extremely simple (the simplest in the Data Link protocol family) and very streamlined

  2. PPP requirements • Pkt framing: encapsulation of packets • bit transparency: must carry any bit pattern in the data field • error detection (no correction) • multiple network layer protocols • connection liveness • Network Layer Address negotiation: Hosts/nodes across the link must learn/configure each other’s network address PPP non-requirements • error correction/recovery • flow control • sequencing • multipoint links (eg, polling)

  3. PPP Data Frame • Flag: delimiter (framing) • Address: does nothing (only one option) • Control: does nothing; in the future possible multiple control fields • Protocol: upper layer to which frame must be delivered (eg, PPP-LCP, IP, IP-CP, etc)

  4. Byte Stuffing • For “data transparency”, the data field must be allowed to include the pattern <01111110> ; ie, this must not be interpreted as a flag • to alert the receiver, the transmitter “stuffs” an extra < 01111101> byte after each < 01111110> data byte • the receiver discards each 01111101 after 01111110, and continues data reception

  5. PPP Link Control Protocol • PPP-LCP establishes/releases the PPP connection; negotiates options • Starts in DEAD state • LCP Options: max frame length; authentication protocol • Once PPP link established, IP-CP (Contr Prot) moves in (on top of PPP) to configure IP network addresses etc.

More Related